In electrical stores, capacitors can most often be seen in the form of a cylinder, inside of which there are many strips of plates and dielectrics.
Capacitor - what is it?
The capacitor is part electrical circuit, consisting of 2 electrodes that are capable of accumulating, focusing or transmitting current to other devices. Structurally, the electrodes are capacitor plates with opposite charges. In order for the device to work, a dielectric is placed between the plates - an element that prevents the two plates from touching each other.
The definition of condenser comes from the Latin word “condenso”, which means compaction, concentration.
Elements for soldering containers are used to transport, measure, redirect and transmit electricity and signals.
Where are capacitors used?
Every novice radio amateur often asks the question: what is a capacitor for? Beginners do not understand why it is needed and mistakenly believe that it can fully replace a battery or power supply.
All radio devices include capacitors, transistors and resistors. These elements make up a board or an entire module in circuits with static values, which makes it the basis for any electrical appliance, from a small iron to industrial devices.
The most common uses of capacitors are:
- Filter element for HF and LF interference;
- Levels sudden surges in alternating current, as well as for static and voltage on the capacitor;
- Voltage ripple equalizer.
The purpose of the capacitor and its functions are determined by the purposes of use:
- General purpose. This is a capacitor, the design of which contains only low-voltage elements located on small circuit boards, for example, devices such as a television remote control, radio, kettle, etc.;
- High voltage. The capacitor in the DC circuit supports the production and technical systems under high voltage;
- Pulse. Capacitive generates a sharp voltage surge and supplies it to the receiving panel of the device;
- Launchers. Used for soldering in those devices that are designed to start, turn on/off devices, for example, a remote control or control unit;
- Noise suppressing. The capacitor in the AC circuit is used in satellite, television and military equipment.
Types of capacitors
The design of the capacitor is determined by the type of dielectric. It comes in the following types:
- Liquid. Dielectric in liquid form is rare; this type is mainly used in industry or for radio devices;
- Vacuum. There is no dielectric in the capacitor, but instead there are plates in a sealed housing;
- Gaseous. Based on the interaction of chemical reactions and used for the production of refrigeration equipment, production lines and installations;
- Electrolytic capacitor. The principle is based on the interaction of a metal anode and an electrode (cathode). The oxide layer of the anode is the semiconductor part, as a result of which this type of circuit element is considered the most productive;
- Organic. The dielectric can be paper, film, etc. It is not able to accumulate, but only slightly level out voltage surges;
- Combined. This includes metal-paper, paper-film, etc. The efficiency increases if the dielectric contains a metal component;
- Inorganic. The most common ones are glass and ceramic. Their use is determined by durability and strength;
- Combined inorganic. Glass-film, as well as glass-enamel, which have excellent leveling properties.
Types of capacitors
The elements of the radio board differ in the type of capacitance change:
- Permanent. The cells maintain a constant voltage capacity until the end of their shelf life. This type is the most common and universal, as it is suitable for making any type of device;
- Variables. They have the ability to change the volume of the container when using a rheostat, varicap or when the temperature changes. The mechanical method using a rheostat involves soldering additional element to the board, while when using a varicond, only the amount of incoming voltage changes;
- Trimmers. They are the most flexible type of capacitor, with which you can quickly and efficiently increase throughput systems with minimal reconstruction.
Operating principle of a capacitor
Let's look at how a capacitor works when connected to a power source:
- Charge accumulation. When connected to the network, the current is directed to the electrolytes;
- Charged particles are distributed on the plate according to their charge: negative ones - into electrons, and positive ones - into ions;
- The dielectric serves as a barrier between the two plates and prevents particles from mixing.
The capacitance of a capacitor is determined by calculating the ratio of the charge of one conductor to its potential power.
Important! The dielectric is also capable of removing the resulting voltage on the capacitor during operation of the device.
Capacitor Characteristics
The characteristics are conventionally divided into points:
- The amount of deviation. Before entering the store, each capacitor must undergo a series of tests on the production line. After testing each model, the manufacturer indicates the range of permissible deviations from the original value;
- Voltage value. Mostly elements with a voltage of 12 or 220 Volts are used, but there are also 5, 50, 110, 380, 660, 1000 and more Volts. In order to avoid capacitor burnout and dielectric breakdown, it is best to purchase an element with a voltage reserve;
- Permissible temperature. This parameter is very important for small devices operating on a 220 Volt network. As a rule, the higher the voltage, the higher the permissible temperature level for operation. Temperature parameters are measured using an electronic thermometer;
- Availability of direct or alternating current. Perhaps one of the most important parameters, since the performance of the designed equipment completely depends on it;
- Number of phases. Depending on the complexity of the device, single-phase or three-phase capacitors can be used. To connect an element directly, a single-phase one is sufficient, but if the board is a “city”, then it is recommended to use a three-phase one, as it distributes the load more smoothly.
What does capacity depend on?
The capacitance of the capacitor depends on the type of dielectric and is indicated on the case, measured in uF or uF. It ranges from 0 to 9,999 pF in picofarads, while in microfarads it ranges from 10,000 pF to 9,999 µF. These characteristics are specified in the state standard GOST 2.702.
Note! The larger the electrolyte capacity, the longer the charging time, and the more charge the device can transfer.
The greater the load or power of the device, the shorter the discharge time. In this case, resistance plays an important role, since the amount of outgoing electrical flow depends on it.
The main part of the capacitor is the dielectric. It has the following number of characteristics that affect the power of the equipment:
- Insulation resistance. This includes both internal and external insulation made from polymers;
- Maximum voltage. The dielectric determines how much voltage the capacitor is capable of storing or transmitting;
- The amount of energy loss. Depends on the configuration of the dielectric and its characteristics. Typically, energy dissipates gradually or in sharp bursts;
- Capacity level. In order for a capacitor to store a small amount of energy for a short period of time, it needs to maintain a constant volume of capacitance. Most often, it fails precisely because of the inability to pass a given amount of voltage;
Good to know! The abbreviation “AC” located on the element body denotes alternating voltage. The accumulated voltage on the capacitor cannot be used or transmitted - it must be extinguished.
Capacitor Properties
The capacitor acts as:
- Inductive coil. Let's take the example of a regular light bulb: it will light up only if you connect it directly to an AC source. This leads to the rule that the larger the capacity, the more powerful the luminous flux of the light bulb;
- Charge storage. Properties allow it to quickly charge and discharge, thereby creating a powerful impulse with low resistance. Used for production various types accelerators, laser installations, electric flares, etc.;
- The battery received charge. A powerful element is capable of maintaining the received portion of current for a long time, while it can serve as an adapter for other devices. Compared to a rechargeable battery, a capacitor loses some of its charge over time, and is also not able to accommodate a large amount of electricity, for example, for industrial scale;
- Charging the electric motor. The connection is made through the third terminal (operating voltage of the capacitor is 380 or 220 Volts). Thanks to new technology, it became possible to use a three-phase motor (with a phase rotation of 90 degrees), using a standard network;
- Compensator devices. It is used in industry to stabilize reactive energy: part of the incoming power is dissolved and adjusted at the output of the capacitor to a certain volume.
Video
A capacitor is a radio-electronic device designed to accumulate electric charge and field energy. There are many types of capacitors and their designs. In this article we will talk about KM type ceramic capacitors. Capacitors of this type are used in industrial equipment, in the manufacture of high-precision radio transmitting devices, as well as in the military industry.
CMs are highly stable; they are designed to operate in pulsed modes, as well as in AC and DC circuits. They are characterized by high adhesion of the plates to ceramics, as well as slow aging, which ensures a low value of the capacitive temperature instability coefficient. KM capacitors, with rather small dimensions, have a high capacity (reaching 2.2 μF). However, the change in capacitance value in the operating temperature range for KM ceramic capacitors ranges from 10 to 90%.
KM group H capacitors are most often used as transition, blocking, etc. Modern KM ceramic capacitors are made by pressing thin metallized ceramic plates into a monolithic block under pressure. Due to the high strength of the mentioned material, it is possible to use very thin workpieces; as a result, the capacitance of the resulting capacitors, proportional to the unit volume, increases sharply.
KM type capacitors also differ from other capacitors in their high price. The reason is that they use the following precious metals (and their mixtures) as dielectric plates: Ag, Pl, Pd. In most cases, palladium is used, which is what determines their value. In this regard, not only new products are in great demand, but also used ones and even those that have fallen into disrepair. Precious metals are contained in capacitors of the KM3-6 type. They are divided into two types: palladium (KM N90) and platinum (KM N30). There is another subtype of KM capacitors of the H30 group - these are KM5 D, which differ from H30 in that they contain much less platinum. The content of precious metals in KM N90 is 46.5 g of palladium and 2.5 g of platinum per kilogram of capacitors. And in capacitors of the KM type N30 is 50 g of platinum per kilogram of capacitors.
Capacitors of group KM D (green) contain 40 g. platinum, that is, 20% less than in capacitors of the H30 group (green). Capacitors of the KM type of the H90 group, which are marked with the letter V, contain 10% more precious metals than capacitors of the H90 group. In theory, such capacitors should be more expensive than other green ceramic capacitors of the H90 group. And smaller capacitors should be cheaper. In practice, all capacitors KM of the H90 group of green color cost the same. The cost of KM capacitors directly depends on the price of precious metals, as well as on the cost of refining costs. The most common ceramic capacitors are KM (the photo shows the external
The name of which it received due to the main color of the body - red and its shades (which is why they are also called “red”). Of course, there are also yellow cases. This type of capacitor is a “pad” of compound that is applied to the capacitor plate and colored red, orange or yellow. The capacities and sizes of these capacitors are different; the output must be bitten off “down to the spine”, so that nothing remains. Despite the high price, a similar “mix”, “mixture” of capacitors various types, of course, differs from the cost of “green” ones to a lesser extent. This is primarily due to the significant mass of the case compared to the contents. Please note that, as a rule, the “yield” in terms of metal content such as , depends largely on many factors, however, it is generally accepted that the smaller the size of the capacitor, the greater the weight of its case and leads inside the case compared to the contents. This is why small capacitors are often cheaper than large ones. Please note that not all capacitors or radio components that are mistaken for “red” capacitors are so. The photo shows examples of directly “red” capacitors that are accepted.
Blockage and unit of measurement of KM capacitors
Very often the mixture contains the so-called “clog” - parts that look like red capacitors, but are not such. This item is a weight position, so it is necessary to weigh the total number of capacitors intended for delivery. It is customary to use the kilogram as a unit of weight, for which the price is given. It's very simple: 100 grams, for example, will be considered as 0.1 kg, 20 grams as 0.02 kg, 7 grams as 0.007 kg. It is worth noting the fact that this item is often delivered in kilograms, 10-15 kilograms each, which is why it is customary to take a kilogram as a unit of weight for calculation.
Where can you find KM capacitors?
Such capacitors can be found in various devices of Soviet and post-Soviet production. As a rule, these are generators, oscilloscopes, and various devices. These elements are placed on the printed circuit boards of the above (and not only) devices, and there are often cases when it is quite possible to get 300 grams of capacitors from one device. To dismantle these capacitors, you need to disassemble the device and remove (bite) the capacitors into some container with pliers, trying to act in such a way that the wire leads of the capacitors remain on the board and not on the capacitor body (as I already wrote “under the spine”). It happens that these capacitors are filled with varnish on the board, glued, there are some outlets, and they have a cambric placed on them. This complicates dismantling and increases blockage. It even happens that in some modules the capacitors are filled with a rubber-like mass, often transparent, which greatly complicates the dismantling of these parts. Directly, usually the capacitor plate inside its painted body looks like a frameless capacitor and is painted beige or brown. When you bite into it, you can see the so-called “layers” that make up the element itself. Look at the photo again, I think that once you remember what the elements of this position look like, you will no longer confuse them with anything, because KM capacitors are rightfully (or rather, in terms of the content of precious metals) one of the most expensive items for which you can earn some good money.
Proper preparation of KM red capacitors
When there are few capacitors, it makes sense to sort them by position, starting at least with size. On the other hand, not everyone is able to do this in accordance with the content of precious metals, which of course differs for different capacitors. When there are already kilograms, they are usually not sorted, but handed over as a “mix” (mixture), some find that sorting is not profitable for them, others, simply due to the fact that their eyesight fails, cannot ensure sorting. This is not scary, because our specialists will help in any case, this is our job. So, having removed the capacitors from the boards, you need to rehang them. To do this, take any container, install it on the scales, and tare the scales (this means that they are reset to zero with the empty container installed. In this case, they will show the weight of only the contents of the container, and not the weight of the can or bag added to it). I explain this because not everyone has worked as a salesperson and knows how to use scales, but this will not be superfluous for control purposes). After this, the happy owner of the “KM Red” calls us by phone, arranges arrival, or pick-up from our side, or specifies the address for. In the case of self-arrival, you receive money immediately, payment is immediate, in the case of parcels - upon receipt and recalculation of the contents, sending to bank card or according to other postal details specified by you.
If you watched the animated series Futurama, you may remember how the robot Bender was overcome by greed and sold his titanium body when prices for it skyrocketed. So, it is this episode that I remember when I sell radio components.
For those who are not in the know.
Almost any electronic component, be it a transistor or a microcircuit, contains precious metals: gold, silver, platinum, palladium, iridium, etc. These metals can be extracted from used and old radio components and then reused.
Luckily, I got my hands on several printed circuit boards with “golden” microcircuits and other radio components. Before this, I was not interested in the delivery of radio components, and I had never even seen gold-plated components. I don’t need a large number of obsolete and identical radio components, and I decided to hand them over. Well, and thereby earn a little extra money. So I became a radio vandal and went over to the side of evil.
Here's the fee.
Let's take a closer look...
In the photo - an integrated stabilizer, a KR142EN1B microcircuit in a case made of “pink” ceramics with gold plated! It is from such microcircuits that gold can be extracted, which is why they are accepted for recycling.
Which radio components contain gold?
Microcircuits containing gold are not common, but they can still be found in old radio equipment. I will show only a few of them.
These are “pink jackets” - decoders 514ID2 (analogous to K514ID2) with gold-plated terminals. The markings indicate that they were manufactured in 1992.
These 514ID1 decryptors will be older, namely, born in 1988. There's more gold on them. Look at the "belly".
This is what gold chips of the 564 series (K564) look like. In this photo: Arithmetic-logical device - microcircuit 564IP3 (analogous to K564IP3) and adder 564IM1 (1KIM1).
Microcircuits 564LS2 (K564LS2). The film on the terminals is varnish. They buy them at a price of about 15 - 20 rubles each.
Hard logic unit - microcircuits 564LE5 (1KLE5). They have golden legs and bellies. On the market they are accepted for 10-12 rubles each. By the way, the microcircuits in such cases are quite compact, they can be used in homemade designs. It will turn out expensive and angry.
This is what the 564LE5, 564LP2, 564TM2, 1KLA8 (564LA8), 564LA7 (1KLA7), 1KLA9 microcircuits look like in a “gold box” type package.
For those who don’t know, microcircuits of the K564 (564), K176, K561, K1561 series are analogues. They were produced in various cases. For example, I saw the K176LA7 microcircuit only in plastic case. And its analogue 1KLA7 (aka 564LA7, K564LA7) was seen both in plastic and in metal case with gold terminals.
In general, as I understand it, microcircuits of the K564 series for military acceptance are marked without the first letter K.
Logic chips 109LI1. This is a 6-input “AND” element for operation with a low-impedance load.
During the Soviet era, precious metals were not spared for the production of electronic components, especially for special-purpose electronics. Then, as now, documentation was compiled for each type of electronic product. It indicated which metals and in what quantity were used to produce one element.
If someone still has an old domestic tape recorder (for example, “Romantic”), then in the instructions for it you can find a page with a table. It indicates the content and quantity of precious metals in the filling of this device.
Subsequently, this made it easier to “evaluate” the product accepted for processing. This is why buyers prefer parts from the Soviet period and treat imports with slight mistrust.
Where can I donate radio components?
You can sell radio components for scrap at any radio market. You've probably already seen signs like "I'll buy expensive radio components." Bring your goods to the buyer (there is one at every radio market), he will announce the price of 1 unit for each type of radio components. If the price suits you, then you give your goods to the buyer, he counts or weighs. In return, you receive cash (i.e. cash). This is the scheme. You can also send parcels with parts by mail to special companies, but I have not tried.
What do you think buyers of radio components love most? Transistors? No. Microcircuits? Nope. And what?! They love ordinary ceramic capacitors of the KM4, KM5, KM6 series.
The fact is that these capacitors contain sufficient quantities of platinum and palladium. One kilogram of KM capacitors costs around several tens of thousands of rubles!
This is what KM5 capacitors look like.
Also prized are “saffron milk caps”, orange-colored KM6 capacitors. I handed over the ones in the photo and the buyer took them without question. But you should understand that if the marking is unclear, even such capacitors may not be accepted. For example, I have seen similar colored capacitors in Chinese amplifiers.
Capacitors are taken by weight and without leads (bitten off). Even if you have 20 grams, they will weigh you and buy it. They say that the more you bring, the higher the price per gram. Honestly, I don't believe it. It all depends on the buyer and price “collusion” on the radio market. All buyers in the market know each other and there is a certain agreement between them. As they explained to me, they all hand over the purchased parts to one person, who regularly comes and buys all the goods in bulk.
The scheme of such a business is quite simple. You buy it at retail at a low price, then sell it wholesale to a company representative from the refinery. You make money on the difference. Something like this.
In any case, when handing over radio components, you need to understand that their cost depends not only on the price of the precious metal on the London Stock Exchange and the dollar exchange rate on a particular day, but also on the buyers. And they also want to live. This is their business. Therefore, before handing over your goods at the first buyer’s stall, I advise you to take a look at the radio market and find out the prices for what you have. For example, I discovered a whole “network” of buyers who accept parts very cheaply.
If the school chemistry course was not in vain for you, then a completely logical thought will pop into your head: “Why not extract precious metals from radio components yourself and sell them?” As far as I know, you can get an ata for this. The fact is that violation of the rules for the delivery of precious metals to the state is punishable by Article 192 of the Criminal Code of the Russian Federation (Chapter 22).
The list of radio-electronic products that are accepted for recycling (purchased) is quite large. These are relays, transistors, switches, toggle switches, capacitors, variable resistors, rheostats, indicators, radio tubes, and even printed circuit boards! Anything that contains precious metals in sufficient quantities. But in most cases, these are, as a rule, radio components produced during the Soviet Union.
At the end of this story, I’ll note.
I do not welcome radio vandalism. After the collapse of the union, a fever began to “destroy” the Soviet heritage. Electronic equipment also fell under this skating rink. Many then made a lot of money on the retail purchase and wholesale of parts containing precious metals. Many years have passed since then, but the business of buying radio components is still alive.
I am for proper recycling. Electronics are a storehouse of precious metals and rare chemical elements. I'm pleased that even from old junk that is usually thrown into a landfill, you can make a little money. The money received can be used to purchase more necessary parts.
The family of capacitors is large in number. These devices can store and release electricity. They can be found wherever there is a current that is directed for the benefit of man. They usually occupy about 15-20 percent of the total number of components. Of these, KM capacitors stand out due to their parameters. What are they and why is there such attention to them?
What are KM capacitors?
What are these devices? This is a ceramic monolithic capacitor, which is made in open-frame and packaged versions. They belong to the subclass of devices that have a constant capacity. KM capacitors are classified as low-voltage devices, the voltage of which can be up to 1600 V. Their capacitance ranges from 16 pF to 2.2 μF. To help you estimate how much it is, you can make a comparison. The entire capacitance of the Earth is approximately 710 microfarads.
Main characteristics
KM capacitors are divided into high-frequency and low-frequency. Depending on their purpose, they belong to one of three groups:
1. This includes those that are characterized by high capacitance stability and low losses.
2. Those that cannot boast of what group No. 1 has.
3. The same as from point No. 2, but there is a slight difference. They are designed to operate in low-frequency circuits.
The greatest interest when choosing is provided by a dozen basic electrical parameters and over twenty-five operational characteristics. There are over 60 of them in total.
Application
The main area of application is work in pulsed, alternating and direct current circuits. They can be used in any equipment: communication systems, household, scientific and measuring equipment, industrial equipment - and this is not a complete list of possible applications. How to avoid mixing up KM capacitors during operation? This type of device is marked directly on it and is represented by an alphanumeric index. Therefore, if you want to purchase one such device, you must first find out how it is designated and what it looks like. When this stage has been completed, you should go to a radio equipment store or market to find a capacitor similar in appearance and corresponding to the indicated marking.
Use of precious metals in construction
The technology of applying materials to the dielectric, as well as their percentage content, has a significant influence. By the way, the majority of palladium (60%) that is used in industry is used for capacitors.
Conclusion
In general, this class of devices can be considered the most popular. Therefore there are problems with searching point of sale, where they can be purchased should not be. But even if you can’t find the model you need in the first store, then it will definitely be found in the next few.
A capacitor is a radio-electronic device designed to accumulate electronic charge and field energy. There are many types of capacitors and their designs. In this article we will talk about clay capacitors of the KM type. Capacitors of this type are used in industrial equipment, in the manufacture of high-precision measuring devices, radio transmitting devices, and also in the military industry.
Clay capacitors KM are distinguished by the highest stability; they are designed to operate in pulsed modes, also in alternating and constant current circuits. They are characterized by the highest adhesion of the plates to the ceramics, as well as slow aging, which ensures a low value of the coefficient of capacitive temperature variability. KM capacitors, with fairly small dimensions, have a high capacity (reaching 2.2 μF). In general, the change in capacitance value in the operating temperature range for KM clay capacitors ranges from 10 to 90%.
KM group H capacitors are in most cases used as transition, blocking, etc. Modern clay KM capacitors are made by pressing thin metallized ceramic plates under pressure into a single block. Due to the highest strength of the mentioned material, it is possible to use very thin workpieces; as a result, the capacity of the purchased capacitors, proportional to the unit volume, increases sharply.
KM type capacitors also differ from other capacitors in their high price. The reason is that they use the following precious metals (and their consistencies) as dielectric plates: Ag, Pl, Pd. Palladium is almost always used, and this is precisely what justifies their value. In connection with this, not only new products are in great demand, but also used ones and even those that have fallen into disrepair. Precious metals are contained in capacitors of the KM3-6 type. They are divided into two types: palladium (KM N90) and platinum (KM N30). There is another subtype of KM capacitors of the H30 group - these are KM5 D, which differ from H30 in that they contain even less platinum. The content of precious metals in KM N90 is 46.5 g of palladium and 2.5 g of platinum per kilogram of capacitors. And in capacitors of the KM type N30 is 50 g of platinum per kilogram of capacitors.
Capacitors of group KM D (greenish) contain 40 g. platinum, in other words, 20% less than in capacitors of the H30 group (greenish). Capacitors of the KM type of the H90 group, which have the letter V in their own marking, contain 10% more precious metals than capacitors of the H90 group. In theory, such capacitors should be more expensive than other clay capacitors of the H90 greenish group. And the smallest capacitors should be cheaper. In practice, all KM capacitors of the H90 group are greenish in color and cost identically. The price of KM capacitors directly depends on the price of precious metals, as well as on the price of refining costs. The most common clay capacitors are KM (photo shows
